1. Field of the Invention
The present invention relates to a display panel having a reflective layer and accompanying manufacturing method.
2. Description of the Related Art
In general, there are two types of liquid crystal displays (LCDs) known as a transmission type and a reflection type. A transmission type has a structure which displays light from a backlight arranged in the back surface side of the LCD panel that permeates the LCD panel and is easily viewable in a dark place. A reflection type has a structure which displays ambient light from the exterior to the inner part of the LCD panel that is reflected by a reflective layer arranged in the back surface side of the LCD panel and is easily viewable in a bright place. In order to realize an LCD panel which is easily viewable in bright as well as dark places, a semi-transmissive type (dual function transmission type and reflection type) LCD panel has been proposed. This is commonly known as a transflective LCD which has a structure that alternately acts as a transmission type and a reflection type LCD panel. When forming the reflective layer in the inner part of the LCD panel, because light from the exterior is not scattered (dispersed) by the reflective layer and light with high luminosity (brightness) is reflected in a specific direction, the display periphery becomes invisible. For this reason, generally, minute irregularities, composed of a number of convex and concave, are formed on the reflective layer surface. A reflection type LCD display panel which has a reflective layer with minute irregularities has been disclosed in Japanese Laid-Open (Kokai) Patent Application No. 2004-020688 titled “DISPLAY DEVICE AND METHOD FOR MANUFACTURING THE SAME.” In the LCD panel described in this conventional prior art reference, a flat reflective layer composed of aluminum is formed on the upper surface of a glass substrate, an insulating film is formed on the upper surface of the glass substrate containing the reflective layer, a plurality of cross-sectional inverted trapezoid-shaped through holes with inclined surfaces are formed in the portion corresponding to the reflective layer of the insulating film and pixel electrodes composed of Indium-Tin-Oxide (ITO) having irregular surfaces follow the irregular surface of the insulating film containing the through holes with inclined surfaces and are formed in the upper surface of the insulating film containing the through holes with inclined surfaces.
Also, as for the LCD devices of the above-mentioned configuration, the flat reflective layer literally has only a light reflection function. Because the pixel electrodes follow the irregular surface of the insulating film containing the through holes with inclined surfaces and are formed in irregular shapes, light scattering functionality is exhibited by refraction in this portion and scatter reflections of outside light (ambient light) are performed as an integral whole.
However, in the LCD devices of the above-described configuration, because light scattering functionality is exhibited by refraction of the pixel electrodes which are composed of ITO and formed in irregular shapes, scattering is minor. Also, because the inclined angle of the through holes with inclined surfaces is uniform, reflected light becomes regular reflectance. Thus, there is a problem that sufficient light scattering reflection is not obtained.